More Excuses for Missing Dark Matter
How long can a theory survive repeated falsifications? Very long, when ideology (and funding) is at stake.
CEH has been reporting on dark matter for many years. They still haven’t found the magic elixir that keeps the big bang theory alive, after a lot of money has been spent on sensitive underground detectors.
ATLAS experiment sets strong constraints on supersymmetric dark matter (Phys.org). Chalk up another failure at detection. Another candidate particle has been ruled out.
Dark matter is an unknown type of matter present in the universe that could be of particle origin. One of the most complete theoretical frameworks that includes a dark matter candidate is supersymmetry. Many supersymmetric models predict the existence of a new stable, invisible particle called the lightest supersymmetric particle (LSP), which has the right properties to be a dark matter particle.
Notice the curious line that dark matter is an “unknown type of matter” that is “present” in the universe. If it is unknown, how do they know it is present? The only reason is that the most popular version of the big bang theory needs it. Two search methods failed to find LSP’s. In physicist lingo, the results “place strong constraints” on the existence of the theoretical particles.
Axions may or may not exist – but we’re not just making things up (New Scientist). Sometimes it’s better not to state that you’re “not just making things up,” because the statement itself arouses suspicions. Chanda Prescod-Weinstein, a theoretical physicist and astronomer, proceeds anyway with that lead-in.
RECENTLY, I visited a prestigious physics department and gave a presentation about my research on a particle called the axion. Fifteen minutes in, a member of the department interrupted me to insist, “Isn’t the axion just a matter of speculation? Shouldn’t you say that?” I had been warned by the graduate students to beware this particular professor, who has a habit of rudely interrupting talks to ask female speakers unnecessary questions. “Yes,” I responded. “I have no idea if the axion is real. Everything theoretical physicists do is speculative, and likely wrong, except for the things we get right.”
Artist conception of dark matter expanding in a field of dark energy.
Axions are a different candidate than LSP’s for dark matter. Have they been detected? Of course not. But the prof is comfortable with that. Implying her male colleague is sexist, she admits that she can’t run an experiment to repeat the first 1 second of the universe, but that doesn’t faze her. She rather enjoys it, prancing merrily into the unknown:
Much like detectives in a mystery novel, we develop ideas about what happened, and then we refine or radically alter those ideas, based on new evidence. Then, we try to convince ourselves and each other that our ideas are good, realistic models of the universe.
There is much we don’t know. The universe certainly doesn’t care if we figure it out. At the same time, it is a great pleasure to do the work of pairing speculative imagination with hard-won data to get to know the universe in this way. I came to study the axion not for its role in the dipole problem, but because it may also be a good candidate to solve a problem of missing, transparent matter – what has historically been called the “dark matter problem“. Axions still might not exist. But their demise would raise so many questions that it is hard to feel worried about that possibility. I say, bring it on.
Dreams and myths also raise questions about other dreams and myths. Does that make dreams a scientific enterprise? Should taxpayers fork out their money for this kind of fruitless quest?
What a fun job: testing your imagination against evidence that never shows up. The department colleague she calls “Dr Sceptic” asked the most scientific question. “Isn’t the axion just a matter of speculation? Shouldn’t you say that?”
A New Filter to Better Map the Dark Universe (Lawrence Berkeley National Laboratory). How can you map something not known to exist? Suppose your theory states that green areas seen from satellites are evidence of gnomes living in the forest. Eggheads at Berkeley are spending a lot of money and erudition on a problem like that. Radiation bathing the universe is well established. That’s like the forest. But dark matter and dark energy are like the hidden gnomes causing the patterns observed.
Distortions in the cosmic microwave background (CMB), caused by a phenomenon known as lensing, can further illuminate the structure of the universe and can even tell us things about the mysterious, unseen universe – including dark energy, which makes up about 68 percent of the universe and accounts for its accelerating expansion, and dark matter, which accounts for about 27 percent of the universe.
Photograph of dark matter. White background provided for contrast.
As often claimed, this leaves only 5% of the universe to consist of things we can actually observe. The dark, mysterious unknown stuff must be there. Theory demands that gnomes outnumber trees by 20 to 1.
They partially justify the work on the basis that it helps answer other questions, too. “One possible application is to develop more detailed visualizations of dark matter filaments and nodes that appear to connect matter in the universe via a complex and changing cosmic web.” The results based on observation may have merit. But in a moment of candor, team member Emmanual Schan made perhaps the most astute observation: “You can be wrong and not know it.”
The dark matter industry sure keeps a lot of bright people busy looking at nothing. If it turns out to be a scam, the Biblical description of these people will be fitting: “And this is the judgment: the light has come into the world, and people loved the darkness rather than the light because their works were evil.” (John 3:19)